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From: Roy Franz <roy.franz <at> linaro.org>
Subject: [PATCH V3 RFC 00/16] EFI stub for ARM
Newsgroups: gmane.linux.kernel
Date: Friday 9th August 2013 23:26:01 UTC (over 3 years ago)
This patch series adds EFI stub support for the ARM architecture.
Some code that was previously only used by x86/x86_64 is now shared
and has been made more general.  The stub for ARM is implemented in
a similar manner to x86 in that it is a shim layer between EFI and
the normal zImage/bzImage boot process, and that an image with the
stub configured is bootable as both a zImage and EFI application.

This patch now (new for v3) series depends on the 
"arm: Add [U]EFI runtime services support" patches by
[email protected]
The Kconfig option now depends on the "CONFIG_EFI" option that his series
adds, and this option will ensure a little endian configuration.  Also, the
EFI support is used to handle the EFI memory map the stub passes to the
There are some minor changes to be coordinated with the EFI runtime
patch series, so I have put this back to RFC status.  These changes should
minor and relate to final device tree bindings.

Changes since v2:
* EFI bugfix "correct call to free_pages" that patch series
  depends on now in mainline
* remove "-fno-stack-protector" from decompressor Makefile.  The current
code doesn't
  trigger the stack protection, so the decompressor now compiles with it
  on.  Note that there has never been any stack protection in the
  since the stack usage doesn't trigger the heuristic in GCC, so right now
  the "-fno-stack-protector" is a noop.
* Changed EFI command line handling to not have a fixed limit.
* Change FDT memory allocation to retry with a larger allocation if
  first educated guess is inadequate.
* Correctly set 'SizeOfCode' in PE/COFF header.
* Reviewed ".setup" section that is in x86 PE/COFF header.  This is used
for x86
  to account for code that is not in the .text section.  We don't need this
  for ARM, as all of our code is in the .text section, or in the PE/COFF
* Moved EFI_STUB_ERROR #define to header file to share between stub C and
* Variety of cleanups and fixes in head.S.
* Changed update_fdt_and_exit_boot() to just update the device tree, and
  renamed appropriately.  Memory allocations moved out of this function as
  well, which enables the retries if the initial FDT size is too small.
  Note that in order to do the retried allocations, the original FDT and 
  command line memory regions are left allocated.  This is OK since the
  has the memory map and will free these allocations along with the initrd
  and new fdt allocations.
* Added prefix to all prints, reduced number of prints, and reviewed all
* Change mixed usage of dtb/fdt to all be fdt or "device tree" in
* remove unnecessary zimage_size variable from relocate_kernel()
* correct return types on EFI functions - should be efi_status_t, not int.

Changes since V1:
* Updated head.S based on feedback from Dave Martin.  ARM/THUMB
  switches now much cleaner.
* Broke up changes to x86 and common code into more patches.
  10 more patches in this series.

Roy Franz (16):
  Move common EFI stub code from x86 arch code to common location
  Add system pointer argument to shared EFI stub related     functions
    so they no longer use global system table     pointer as they did
    when part of eboot.c.     This code is now shared, so using a
    global variable     as part of the interface is not that nice.
    Also,     by avoiding any global variables in the ARM EFI stub,    
    this allows the code to be position independent without    
    requiring GOT fixups.
  Rename memory allocation/free functions
  Add minimum address parameter to efi_low_alloc()
  rename __get_map() to efi_get_memory_map(), add parameter     to
    optionally return mmap key. The mmap key is required     to exit
    EFI boot services, and allows efi_get_memory_map()     to be used
    for getting final memory map.
  Enforce minimum alignment of 1 page on allocations.     The
    efi_high_alloc() and efi_low_alloc() functions     use the
    EFI_ALLOCATE_ADDRESS option to the EFI     function
    allocate_pages(), which requires a minimum     of page alignment,
    and rejects all other requests.
  Allow efi_free() to be called with size of 0, and do nothing in that
  Generalize handle_ramdisks() and rename to handle_cmdline_files().
  Renames in handle_cmdline_files() to complete generalization.
  Move EFI_READ_CHUNK_SIZE define to shared location.
  Add proper definitions for some EFI function pointers.
  Fix types in EFI calls to match EFI function definitions.
  resolve warnings found on ARM compile
  Add strstr to compressed string.c for ARM.
  Add EFI stub for ARM
  Add config EFI_STUB for ARM to Kconfig

 arch/arm/Kconfig                       |   11 +
 arch/arm/boot/compressed/Makefile      |   15 +-
 arch/arm/boot/compressed/efi-header.S  |  111 +++++++
 arch/arm/boot/compressed/efi-stub.c    |  448 ++++++++++++++++++++++++++++
 arch/arm/boot/compressed/efi-stub.h    |    5 +
 arch/arm/boot/compressed/head.S        |   90 +++++-
 arch/arm/boot/compressed/string.c      |   21 ++
 arch/x86/boot/compressed/eboot.c       |  490
 arch/x86/boot/compressed/eboot.h       |    9 -
 drivers/firmware/efi/efi-stub-helper.c |  505
 include/linux/efi.h                    |   51 +++-
 11 files changed, 1263 insertions(+), 493 deletions(-)
 create mode 100644 arch/arm/boot/compressed/efi-header.S
 create mode 100644 arch/arm/boot/compressed/efi-stub.c
 create mode 100644 arch/arm/boot/compressed/efi-stub.h
 create mode 100644 drivers/firmware/efi/efi-stub-helper.c

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